Baltimore placed Hammel on the 15-day disabled list Sunday.
Hammel's knee has been bothering him since May, but the injury became more serious Friday night when he was forced to leave a game against Detroit after throwing a pitch in the fourth inning.
CUETO QUESTIONABLE: The Reds aren't sure whether right-hander Johnny Cueto will be able to start as planned on Tuesday because of a blister on the index finger of his pitching hand.
The first-place Reds aren't used to worrying about a starter. Cincinnati has used only five different starters, the first time in modern franchise history that it's gone this deep into the season with its rotation intact.
Cueto was supposed to start on Sunday night against the St. Louis Cardinals, but was pushed back two days after he developed the blister during a bullpen session. The current plan is to have Cueto pitch against Arizona on Tuesday.
Manager Dusty Baker was waiting to see how Cueto's finger responds to treatment before deciding whether to consider other options for next Tuesday's game.
ASTROS SHELVE LOWRIE, CASTRO: The Houston Astros placed infielder Jed Lowrie and catcher Jason Castro on the disabled list on Sunday.
Lowrie was injured during a collision at second base in the third inning of Houston's 12-inning 3-2 loss to the San Francisco Giants on Saturday. Lowrie suffered a sprained right ankle and damaged a nerve in his right leg.
Castro has been bothered by soreness in his right leg, the same one he had surgery on in March 2011. Astros manager Brad Mills had hoped Castro could avoid the DL and previously talked about the possibility of putting him in the lineup Sunday before the team decided to make the move.
- Live streams: 4A & 5A baseball tournament...
- Looking back: Ray Harroun wins 1st...
- UCLA agrees to 15-year deal with Under Armour
- Atlanta, Miami, Los Angeles selected to host...
- Even before easy win, good day for Serena...
- Westbrook, Thunder put Warriors on brink of...
- 'Lost my way': Murray pushed to 5 sets again...
- USMNT: RSL's Beckerman starts, Timbers' Nagbe...
- ESPN's Jake Trotter says it's 'Big 12... 152
- Morning links: Broncos like Devontae... 68
- Brad Rock: BYU-Utah hoops are back... 51
- Rivalry renewed: BYU, Utah agree to a... 49
- Brad Rock: This is the Big 12 —of... 41
- Morning links: BYU shirt summits Mt.... 37
- Why can't we be friends? BYU-Utah fans... 31
- Video: 100 days until college football... 27